Add pyscn to Python tools

[DaisukeYoda]

Summary

Adds pyscn to the Python static analysis tools list.

pyscn is an intelligent Python code quality analyzer written in Go that performs deep, structural static analysis:

• CFG-based cyclomatic complexity analysis — builds control-flow graphs from tree-sitter ASTs to calculate McCabe complexity
• Multi-algorithm clone detection (Type 1-4) — textual (FNV hash), normalized AST (Jaccard), structural (APTED tree edit distance), and semantic (CFG-based) clone detection
• Dead code detection — identifies unreachable code after return/break/continue/raise and unreachable conditional branches
• Coupling metrics (CBO) — analyzes class dependencies for maintainability assessment
• Uses tree-sitter for robust Python parsing
• ~980 GitHub stars, actively maintained, MIT licensed

Checklist

• Tool is actively maintained (multiple contributors)
• Tool has more than 20 GitHub stars (~980)
• Project is mature (exists for more than three months)
• Entry added as YAML in data/tools/pyscn.yml
• Description is under 500 characters
• License specified (MIT)

[DaisukeYoda]

@mre friendly ping 🙂 Open since March and still green. I just refreshed the entry to point homepage/resources at the docs site. pyscn is at ~1k stars, MIT, actively maintained. Happy to tweak anything if needed, thanks!